More and more electronic devices, such as video cameras, TV sets, and surround sound systems comprise a remote control functionality, which control functionality can be used by using an external remote control terminal. The external remote control terminals are typically either device specific and tailored according to the functions and the proposed needs and desires of a user, or programmable to enable controlling of various devices.
It is well known to use infra red (IR) frequencies for the transmission of control signals from the remote control to the device to be controlled. One drawback of IR remote controls is that IR frequencies behave like electromagnetic light in the sense that free eyesight is needed between the remote control and the controlled device to successfully transfer control signals by using IR from the remote control to the device to be controlled by using normal transmission power levels. Another disadvantage is that the remote control often has to be directed to the device to be controlled because the IR light often is transmitted in a relatively little solid angle straight ahead.
It is also known to use diffus IR light, that is, to transmit IR light in a larger solid angle and to enable receiving control signals in a similar manner in a larger solid angle. By transmitting control signals from a remote control to a device to be controlled by using such a diffus IR light technique, the directioning of the remote control toward the device to be controlled may become less critical. However, the drawback of requiring free eyesight between the remote control and the device to be controlled remains unchanged for normal transmission power levels.
An alternative to transmitting IR signals is to transmit radio frequency signals between a remote control and the device to be controlled. This is also well known and is used in various applications, such as radio-controlled toys, garage door maneuvering functions, bomb disarming robots, etc.
When remotely controlling a toy or when opening or closing the garage door, a remote control terminal is used for transmitting the control signals over the air. The remote control, being an extra item to bring along, has to be localized and needs to be available for the user to be able to remotely control the toy or the garage door, for example. Looking for a remote control terminal in the car, for instance, under way can also be hazardous because attention is at least momentarily not focused on safely driving the vehicle.
Moreover, it is well known to use the Bluetooth™ wireless radio communication system for remotely controlling electronic devices. One drawback with the Bluetooth™ system, is that the Bluetooth™ radio communication module, which is currently needed for the radio communication using Bluetooth™, is still expensive. As both the remote control terminal as well as the electronic device to be controlled are required to comprise a Bluetooth™ module, both these items become expensive. It is noted that Bluetooth™ was designed for more demanding applications requiring a larger bandwidth, such as for wireless voice calls.
There is hence still a need to overcome the various disadvantages and drawbacks of the prior art techniques.